Not receiving emails from previously safe senders

I haven't been able to find a solution to my specific problem yet,
but the issue is that outlook (on both the app and website) has stopped receiving emails from Roblox (specifically), this has happened with a different email account of mine where it stops receiving emails from a certain company. Previously I had been able to receive emails just fine, the last email I received from Roblox was in January, and after not accessing the account for a couple months it has stopped receiving Roblox emails (in general), and I've already determined that it is not a Roblox issue.
If there is any incredibly specific way to somehow start receiving emails from a sender that you haven't blocked or anything then I would appreciate the help.